In a statement posted to his Facebook account Wednesday evening, Christie writes:
"I ran for president to say that the government needs to once again work for the people, not the people work for the government. And while running for president I tried to reinforce what I have always believed - that speaking your mind matters, that experience matters, that competence matters and that it will always matter in leading our nation. That message was heard by and stood for by a lot of people, but just not enough and that's ok."
"I have both won elections that I was supposed to lose and I've lost elections I was supposed to win and what that means is you never know what will happen. That is both the magic and the mystery of politics - you never quite know when which is going to happen, even when you think you do."
"And so today, I leave the race without an ounce of regret. I'm so proud of the campaign we ran, the people that ran it with me and all those who gave us their support and confidence along the way. Mary Pat and I thank you for the extraordinary display of loyalty, friendship, understanding and love."
ABC News reports Christie held a meeting with his campaign staff at 4 p.m. Wednesday to thank them and announce the news.
Christie also called key supporters and donors to inform them of his decision and thank them for their support.
Earlier Wednesday, Christie cancelled an event in South Carolina on the heels of his disappointing finish in the New Hampshire GOP primary.
The event was a forum on legal and constitutional issues set for Charleston, says Brielle Applebaum of the Conservative Leadership Project.
South Carolina is next up on the GOP primary calendar and votes on Feb. 20.
Christie told a crowd of supporters in New Hampshire on Tuesday night that he was headed home to New Jersey to "take a deep breath" and assess what comes next.
On Wednesday morning, Donald Trump said he talked with Christie a "little bit" about the New Jersey governor dropping out of the race for the GOP presidential nomination.
Trump said on "CBS This Morning" that he and Christie spoke after the New Hampshire primary Tuesday, in which Trump won a big victory.
Seeking endorsements from any rivals that quit the race, Trump said of Christie, "He's a friend of mine. I'm surprised he didn't do better."
He adds, "I'd like to see a lot of people drop out."
The Associated Press contributed to this report.